Jan. 13 (Bloomberg) -- Lockheed Martin Corp.’s F-35
fighter, the U.S.’s top weapons program, had “mixed results”
in tests last year of its flight characteristics and combat
systems, according to a Pentagon report.

Director of Operation Test and Evaluation Michael Gilmore
wrote in the report that the three versions of the aircraft in
2011 matched or exceeded the program’s restructured plan for
tests designed to evaluate flying qualities. The jet in 2010 met
most test goals after falling behind in 2009.

Flights designed to accomplish discrete events to
demonstrate the aircraft’s war-fighting systems, such as
navigation, enemy identification and targeting, fell behind 11
percent for the Air Force and 9 percent for the Marine Corps
versions. The Navy’s aircraft carrier version is 32 percent
ahead of schedule, the tester says.

The $382 billion F-35 Joint Strike Fighter is the
Pentagon’s largest program. It plans to buy 2,443 jets for the
Air Force, Navy and Marine Corps.

Production funding is estimated by the Pentagon to increase
from the requested $6.9 billion this year to $14.2 billion in
fiscal 2016.

Gilmore’s 13-page assessment is contained in his annual
report on weapons testing that the Pentagon released today.
Bloomberg News obtained a copy in advance.

Lockheed’s Response

“The report recognizes the numerous accomplishments of the
F-35 program in 2011 such as the outstanding results from F-35
ship trials, completion of F-35C structural testing and the fact
flight sciences and flight testing either matched or exceeded
plan in 2011,” Lockheed spokesman Michael Rein said today in an
e-mailed statement.

Flight tests in the report covered only the period through
November, he said. Through December, “the flight test team
completed 7,823 test points, an increase of 1,744 test points
over the number published.”

The F-35 flight-test plan for last year called for the
accomplishing 6,622 test points, Rein said.

Whether to Delay

The report outlines numerous challenges the test program
faces as the Pentagon decides whether to delay purchasing 100 to
150 aircraft after 2017, the last year in the military’s five-year defense plan.

The report provides a neutral assessment of Lockheed Martin
test progress that will be reviewed by lawmakers and the public
throughout the fiscal 2013 budget process.

The short-takeoff and vertical landing Marine Corps model
was placed on “probation” last year by then-Defense Secretary
Robert Gates because of reliability and other problems. It’s the
most complex model of the three versions.

The Marine Corps version in October successfully conducted
initial trials from a ship at sea.

“However, significant work and flight tests remain to
verify and incorporate modifications to aircraft required to
correct known deficiencies and prepare the system for
operational use,” Gilmore wrote.

“A significant amount of flight test and development
remains to be accomplished” with some troubled components,
including the propulsion system’s drive shaft, clutch and an
actuator, he said.

Mixed Progress

The three variants exceeded by 105 the 812 test flights
planned for last year. The flight program exceeded by 570 the
number of planned test “points,” or planned flying events. It
exceeded by 56 the 133 flights devoted to testing mission
systems. Gilmore wrote.

“Overall, the program has demonstrated very little
missions systems capability thus far in flight test,” Gilmore
wrote. “In fact, the program has not delivered some of its
intended initial training capability, such as effective and
consistent radar performance.”

Gilmore said the 63 aircraft produced under Lockheed’s
first four initial production contracts “will require
significant numbers of structural modifications and upgrades to
attain the planned service life” and full combat capability.

Rein said “the individual technical issues cited in the
report are known issues that have engineering solutions either
identified, in work or are currently in flight test.”

The assessment follows a team of Pentagon test, systems
engineering and structural experts who concluded in a Nov. 29
report that “no fundamental design risks” would preclude
production of the jet for the Air Force, Navy and Marine Corps.

It identified 13 current or likely test issues of varying
severity, the combined effect of which “results in a lack of
confidence” in the aircraft’s “design stability.” The issues
include the Navy version’s tailhook for aircraft carrier
landings, the system for dumping extra fuel before landing and
excessive aircraft shaking during flight.